Phosphorus is a nutrient vital to human, animal, and plant life. It is one of the most common substances in our environment, naturally occurring in our food, water, and bodies, as well as, in human and animal waste. However, excess phosphorus in freshwater systems can lead to undesirable consequences. For example, an excess amount of phosphorus in bodies of water can lead to accelerated plant growth, algae blooms, low dissolved oxygen, and death of certain fish, invertebrates and other aquatic animals.
Inorganic phosphate and organic phosphorus acids can often be found in byproducts from manufacturing plants, animal production facilities, detergents, wastewater, and storm water. Effluent streams from such plants commonly contain inorganic phosphate and organic phosphorus acids, which may be discharged into rivers and lakes. Municipal wastewater may contain from 5 to 20 mg/l of total phosphorus, of which 1-5 mg/l is organic and the remaining in inorganic form. Realizing the undesirable effects of excess phosphorus in water, countries and municipalities have imposed limits on the amount of phosphorus that may be permitted in effluent streams.
Phosphorus may be removed from streams using filtration for particulate phosphorus, membrane technologies, precipitation, assimilation, or enhanced biological phosphorus removal methods. For precipitation, inorganic phosphates may be removed by adding a coagulant and mixing the wastewater and coagulant mixture through the use of multivalent metal ions, such as calcium, aluminum and iron. Organic phosphorus typically is removed by converting to inorganic phosphates and precipitating using conventional methods. Nonetheless, most phosphorus removal treatments mainly target the removal of inorganic phosphates, but do not target or optimize the removal of organophosphorus acids in the water stream. These water streams with organic phosphorus acids are released into rivers and lakes. Hence, potentially causing harm to the environment.
The need therefore exists for methods for reducing the amount of organic phosphorus acids that is contained in effluent streams without converting it to inorganic phosphorus species.